Not applicable.
The present invention relates generally to automotive safety and, more particularly, to an apparatus that provides a driver with an indication of the position and closing speed of an overtaking vehicle in an adjacent highway lane.
In view of the dangers associated with automotive travel, there is an ongoing need for enhanced automotive safety features. One possible area of increased automotive safety involves improving the driver""s ability to see obstacles that are near his or her vehicle, but which are in locations that are difficult to observe from the driver""s position, commonly referred to as xe2x80x9cblind spots.xe2x80x9d Hereinafter, the driver""s vehicle may be referred to as the xe2x80x9chost vehicle.xe2x80x9d
Every year there is an increase in the number of vehicles on the nation""s highways, particularly the roads of the Interstate Highway System. These roads are multiple lane highways, with two, three or even more lanes of travel in each direction. Vehicular traffic flows in all lanes with seemingly little regard for the principle that slower vehicles should travel in the rightmost lane and passing traffic in the left lane. In addition, a vehicle exiting such a highway may have to make two or more lane changes to reach the exit lane.
In view of the proliferation of multiple lane highways, the increase in traffic congestion, and the plethora of distractions that contribute to driver inattention, such as CDs and tapes, snacks and beverages, pagers and mobile telephones, perhaps the most likely cause of an accident while traveling on a multiple lane highway is the maneuver of changing from one lane to another.
In order to make a lane change with complete safety, a driver must have a clear indication of the presence of other vehicles in the adjacent lane to which he or she intends to enter, and must additionally be able to determine whether any such vehicles in the adjacent lane is approaching the host vehicle at a rate which would make such a maneuver unsafe.
The rear view vision of automobile and truck drivers has been enhanced by the use of mirrors to aid in determining whether obstacles are present in a blind spot. Such mirrors have been made in a variety of shapes and mounted in various locations to provide the driver with the greatest ability to detect obstacles in particular blind spots. As an example, convex outside right-side mirrors have become standard equipment on most automobiles. These convex mirrors increase the angle of the driver""s vision; however, they provide a misleading indication as to the distance between the host vehicle and a sighted object. Mirrors provide the driver with some information regarding the presence of obstacles in certain of a vehicle""s blind spots, but they are less useful at night and under adverse weather conditions. Furthermore, the driver must rely on visual and mental extrapolations to determine whether another vehicle sighted in a rearview mirror in an adjacent lane is closing on the host vehicle at such a rate that it would be imprudent for the host vehicle to make a lane change maneuver.
Prior art solutions to this problem include side object detectors that operate well in a static environment, but are deficient in dynamic traffic situations. As an example, in U.S. Pat. No. 5,517,196, xe2x80x9cSmart Blind Spot Sensor With Object Ranging,xe2x80x9d a radar transceiver transmits a multi-frequency radio signal at a blind spot of the vehicle. The received reflected signal is processed to detect only those objects within a pre-established range and which are moving at approximately the same speed as the vehicle.
Such a system, while providing an indication of the presence of a moving object in or near a blind spot, fails to provide sufficient information to the driver of the host vehicle to make an informed determination as to the prudence of executing a lane change.
In view of the above-stated problems and limitations of existing automotive blind-spot detection systems and in accordance with the present invention, it has been recognized that combining the need for increased automotive safety with the usefulness and desirability of blind-spot detection leads to the problem of providing a blind-spot detection apparatus which is simple, informative, easy to use and understand, cost-effective and reliable, given the environmental and other operating conditions under which such an apparatus must operate. It would, therefore, be desirable to fill the need for a device that provides an easily interpreted indication of the position and closing speed of an overtaking vehicle in an adjacent highway lane.
In accordance with the principles of the present invention, there is disclosed herein a safety device for an automotive vehicle. The device includes a multibeam scanning radar system having a transmit/receive module mounted on a side surface of the vehicle. The radar system provides a plurality of scanning beams at discrete angular sectors along the side of the vehicle, the radar system generating a plurality of signals signifying the presence of an obstacle within a corresponding sector. The safety device also includes an equal plurality of indicators each coupled, respectively, to one of the signals, each indicator providing a visual indication of the presence of an obstacle within a corresponding sector. The indicators are configured in an array that meaningfully displays a transition of an obstacle from one of the sectors to another.
In a preferred embodiment of the present invention, the visual indicators are configured as a column of light-emitting diodes (LEDs) affixed to the outside mirrors of the host vehicle. Further in accordance with the preferred embodiment, the multibeam electronically scanned radar system provides coverage of between 90 and 180 degrees, preferably 150 degrees, via at least four, and preferably eight, scanned beams subtending equal angles, each beam position coupled to illuminate one of an equal number of LEDs. Still further in accordance with the preferred embodiment, the host vehicle is equipped with two such multibeam electronically scanned radar systems, thus providing 90- to 180-degree coverage on both sides of the vehicle, the left and right side radar systems being coupled to LEDs in the lefthand and righthand outside mirrors, respectively.